Various known lens systems exhibit a large field of view. For example, U.S. Pat. No. 3,884,556, to Jihei Nakagawa, entitled "Retrofocus Wide-Angle Lens System," describes a compact retrofocus wide-angle lens system in which aberrations are corrected using a positive meniscus lens with a large power as the first lens, negative meniscus lenses as second and third lenses, and a thick positive lens as a fourth lens.
U.S. Pat. No. 4,145,116, to Yoshitsugi Ikeda, entitled "Large Aperture Ultra Wide Angle Photographic Lens System," describes a large aperture ultra-wide angle photographic lens system with a lens diameter small enough to be compatible with filters designed for use with other lens systems, and which permits the correction of various optical aberrations.
U.S. Pat. No. 4,394,073, to Koichi Wakamiya, entitled "Compact Wide Angle Lens," discloses a compact wide angle lens comprising, in succession from the object side, a first component which is a positive meniscus lens having its convex surface facing the object side, a second component which is a biconcave lens, a third component which is a positive lens having its surface of sharper curvature facing the object side, a fourth component which is a positive lens, and a fifth component which is a negative meniscus lens having its convex surface facing the image side. The compact wide-angle lens has a total length as short as the focal length thereof, and yet has a small rearward lens aperture.
Nakagawa provides a compact retrofocus wide-angle lens system. Ikeda discloses a large aperture ultra-wide-angle photographic lens system. Wakamiya discloses a compact wide angle lens system comprising a series of lenses. Nakagawa, Ikeda, and Wakamiya all relate to the use of wide angle lenses to correct for aberrations, or to allow for more compact camera designs.
Now, for the first time and in contrast to the prior art, the present invention teaches the design of a single UV imaging lens package capable of detecting a target to within 9.degree. using an extremely wide angle, very large aperture, and compact solar blind lens.